The California crash also occurred on the same day that a Marine Harrier jet crashed during takeoff from an airport in the East African nation of Djibouti. The pilot managed to eject and was being medically evaluated, military officials said.

The CH-53E Super Stallion is the largest helicopter in the U.S. military. It is used for minesweeping and transport and can carry dozens of troops and tons of cargo.

Two years ago, 12 Marines died when two of the helicopters collided off the coast of Oahu in Hawaii.